Ignore post_content when searching with Relevanssi

relevanssi_content_boost.php

<?php
// For all post types
add_filter( 'relevanssi_index_content', '__return_false' );

// For some post types
add_filter( 'relevanssi_post_content', function( $post_content, $post_object ) {
    if ( in_array( $post_object->post_type, array( 'post', 'other_cpt' ) ) ) {
        return '';
    }
    return $post_content;
} , 10, 2 ;


// OLD VERSION - Remove weight (works, but versions above make more sense)
// Relevanssi does not seem to have a way to not index post_content
// And even if try you set the weight to zero, the interface will save "1", because of this:
// - https://plugins.trac.wordpress.org/browser/relevanssi/tags/4.24.6/lib/options.php#L49
// - https://plugins.trac.wordpress.org/browser/relevanssi/tags/4.24.6/lib/utils.php#L1618
// So, by forcing the option to 0, Relevanssi will effectly NOT use post_content when searching
add_action( 'update_option_relevanssi_content_boost', 'my_remove_relevanssi_content_boost', 10, 2 );
function my_remove_relevanssi_content_boost( $old_value, $new_value ) {
    remove_action( 'update_option_relevanssi_content_boost', 'my_remove_relevanssi_content_boost', 10, 2 );
    update_option( 'relevanssi_content_boost', 0 );
}